This invention relates to a flushing apparatus for urinals, and paricularly to that type of flushing apparatus having an automatic flush device controlled by an infrared emitting-and-detecting control device and so arranged that a fixed flushing operation will be automatically effected, and a manual flush device which a user operates by pushing a manual button.
At present, the conventional flushing apparatus for man's stall urinal is confined to the following three types:
(1) The manual type uses the hand to press the flushing valve fixed on the water pipe thereof for activating the flushing operation. The problems of this type are (1) if the water pressure is low, flushing cannot be accomplished therewith; (2) most users usually either forget to flush or do not know how to use it; (3) it is easily contaminated with contagious diseases through hand operation.
(2) The timing type uses a timer to open and close a water valve for a time-fixed flushing operation. The problems of this type are: it is ineffective to keep the urinal clean because of the fixed time interval; and it consumes too much water during the time the urinal is not used at all.
(3) The automatic flushing type uses supersonic or infrared devices to effect the flushing operation. In the supersonic type, error actions often occur in the flushing operation since the stall urinals are installed in a public lavatory with close array, which is susceptible to erroneous sound reflection and causes error operation. The infrared type may result in a more reliable flushing operation, and there are some associated products thereof on the market. A related discussion of the development of the infrared-type flushing apparatus is provided in R.O.C. Patent No. 19708, issued on Oct. 6, 1983, to Mr. Lin. The operation of the patented evice is similar to that of the present invention, but has a different structure. A portion of the above mentioned No. 19708 is incorporated by reference.
Referring to FIG. 1, No. 19708 provides a floating piston 10 provided with an electromagnetic valve 101 controlled by an infrared control device which is not shown, swinging pole 102, passages for the water flow, and a manual button 103. The problems of such an apparatus are that there are many elements and passages located in the floating piston 10, so that long life of the piston and reliability of the flushing operation are doubtful. Take for example the way in which the power of the electromagnetic valve is connected, and the requirement of water-tightness. The large volume of the floating piston may influence the sensitivity and assurance of the operation thereof caused by water pressure. Because the swinging pole has two operation functions, including automatic and manual control, which may interfere with each other, when the swinging pole cannot return to its initial position after being displaced by the manual button, water will continuously drain out, and this will affect the operation of the electromagnetic valve thereafter. When the electromagnetic valve is damaged, the operation of the manual button will also be affected, and if there are no new parts for immediate supply, all functions of the flushing apparatus will be lost, including the manual operation.